Solid dispersion, method for producing the same, chain-extended polyurethane using the same, and epoxy resin composition containing the same

Abstract

The present invention relates to a solid dispersion, a manufacturing method thereof, a chain-extended polyurethane using the same, and an epoxy resin composition containing the same. More specifically, the present invention relates to a solid dispersion, a manufacturing method thereof, a chain-extended polyurethane using the same, and an epoxy resin composition containing the same, which uses an isotropic and / or anisotropic material of inorganic or organic origin as a dispersoid and disperses the dispersoid in a dispersion medium such as a polyol or a sugar that is solid at room temperature, thereby enabling easy storage and use, reducing transportation costs, preventing or reducing aggregation and precipitation that occur during product storage, improving work efficiency and reducing process costs, and improving strength when applied to polyurethane, thereby providing improved strength compared to conventional curing agents.

Description

[Technical Field]

[0001] The present invention relates to a solid dispersion, a manufacturing method thereof, a chain-extended polyurethane using the same, and an epoxy resin composition containing the same. More specifically, the present invention relates to a solid dispersion, a manufacturing method thereof, a chain-extended polyurethane using the same, and an epoxy resin composition containing the same, which uses an isotropic and / or anisotropic material of inorganic or organic origin as a dispersoid and disperses the dispersoid in a dispersion medium such as a polyol or a sugar that is solid at room temperature, thereby enabling easy storage and use, reducing transportation costs, preventing or reducing aggregation and precipitation that occur during product storage, improving work efficiency and reducing process costs, and improving strength when applied to polyurethane, thereby providing improved strength compared to conventional curing agents. [Background technology]

[0002] Isotropic and / or anisotropic materials of inorganic or organic origin are used as major materials in fields such as lightweight materials, hybrid materials, surface protective agents, conductive pastes, conductive inks, sensors, precision analytical elements, optical memories, liquid crystal display elements, nanomagnets, thermoelectric media, high-performance catalysts for fuel cells, organic solar cells, nanoglass devices, abrasives, drug carriers, environmental catalysts, paints, printing inks, inkjet inks, color filter resists, inks for writing instruments, etc. In this regard, the isotropic and / or anisotropic materials of inorganic or organic origin are used industrially as substances that efficiently improve processing characteristics, product characteristics, and material physical properties by preparing and utilizing a dispersion of fine particles in an aqueous dispersion medium or a non-aqueous dispersion medium, thereby contributing to quality stabilization and improved yield during production.

[0003] However, when changing the dispersoid material, reducing particle size, or controlling particle shape, it becomes difficult to stably disperse the dispersoid, and the dispersoid may aggregate or precipitate in the dispersion medium within a short period of time. The aggregation and precipitation problems of dispersoids lead to reduced productivity, processing characteristics, handling characteristics, and product yield in the production of dispersions, as well as reduced characteristics, material properties, and quality of the final product. Furthermore, they are known to cause undesirable phenomena in appearance, such as reduced transparency, gloss, and coloring strength, color unevenness, and cracking. Dispersants are used to suppress such aggregation and precipitation of dispersoids and achieve dispersion stabilization.

[0004] Previously, attempts have been made to obtain stable dispersion compositions by using dispersants to suppress aggregation of dispersions, as disclosed in Patent Documents 1 and 2. However, from the viewpoints of diversifying dispersion media and dispersoids, miniaturizing dispersoid particle sizes, diversifying particle shapes, improving the quality of final products, improving productivity, and high demands for processability, previously proposed dispersants did not sufficiently satisfy the required properties.

[0005] The biggest problem with conventional dispersion compositions is that when a dispersion composition using water as a dispersion medium is applied to polyurethane resins, epoxy resins, etc., an additional step of preparing a masterbatch of water and polyol or a masterbatch of water and epoxy is sometimes required, and a surfactant is required to prevent aggregation of the dispersoids.

[0006] Therefore, there is a need to develop a dispersion and a dispersion composition that can prevent or improve the aggregation and precipitation of dispersoids without using a separate dispersant or surfactant, and to develop a chain extender for applying the dispersion to polyurethanes and an epoxy resin composition that uses the dispersion as a curing agent. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Korean Patent Publication No. 10-2013-0023254 [Patent Document 2] Korean Patent Publication No. 10-2013-0096307 Summary of the Invention [Problem to be solved by the invention]

[0008] In order to solve the above-mentioned problems, the present invention provides a solid dispersion, which uses an isotropic and / or anisotropic material of inorganic or organic origin as a dispersoid and disperses it in a dispersion medium such as a polyol or a sugar that is solid at room temperature, thereby making it easy to store and use, reducing transportation costs, preventing or improving aggregation and precipitation phenomena that occur during product storage, improving work efficiency, reducing process costs, and improving strength when applied to polyurethanes, thereby providing improved strength compared to conventional curing agents; a method for producing the solid dispersion; a chain-extended polyurethane using the solid dispersion; and an epoxy resin composition containing the solid dispersion. [Means for solving the problem]

[0009] In order to solve the above-mentioned technical problems, a first aspect of the present invention provides a solid dispersion comprising a dispersoid and a dispersion medium in which the dispersoid is dispersed, wherein the dispersoid is organic particles, inorganic particles, or a mixture thereof, and the dispersion medium is a non-aqueous dispersion medium that is in a solid state at room temperature.

[0010] According to another aspect of the present invention, there is provided a dispersion composition comprising the solid dispersion.

[0011] According to yet another aspect of the present invention, there is provided a method for producing a solid dispersion, comprising the steps of mixing a dispersoid and a dispersion medium; and melting the dispersion medium in the mixture, wherein the dispersoid is organic particles, inorganic particles, or a mixture thereof, and the dispersion medium is a non-aqueous dispersion medium that is in a solid state at room temperature.

[0012] According to yet another aspect of the present invention, there is provided a chain-extended polyurethane produced by reacting a polyurethane prepolymer with the solid dispersion described above.

[0013] According to yet another aspect of the present invention, there is provided a method for producing a chain-extended polyurethane, comprising: (1) adding the solid dispersion to a polyurethane prepolymer; and (2) reacting the mixture obtained in step (1).

[0014] According to yet another aspect of the present invention, there is provided an epoxy resin composition comprising: an epoxy resin; and the solid dispersion.

[0015] According to yet another aspect of the present invention, there is provided a method for producing an epoxy resin composition, comprising the step of mixing an epoxy resin and the solid dispersion.

[0016] According to yet another aspect of the present invention, there is provided a cured product obtained by curing the epoxy resin composition.

[0017] According to yet another aspect of the present invention, there is provided a molded article comprising the cured product. [Effects of the Invention]

[0018] The solid dispersion according to the present invention, in which an isotropic material and / or anisotropic material of inorganic or organic origin is dispersed, can reduce or eliminate aggregation during product storage, thereby shortening the process input time when using the product (solid dispersion), reducing or eliminating the additional process or time required to redisperse the aggregated product, and improving work efficiency because there is little or no concern about worker labor and safety during such additional work. Furthermore, the solid dispersion of the present invention has a large amount of dispersoid uniformly dispersed therein, and when used as a chain extender for polyurethane, it can improve the strength compared to conventional chain extenders. When used as a curing agent, it can provide a cured product of an epoxy resin with improved strength compared to conventional curing agents. DETAILED DESCRIPTION OF THE INVENTION

[0019] The present invention will be described in detail below. The present invention relates to a solid dispersion comprising a dispersoid and a dispersion medium in which the dispersoid is dispersed, wherein the dispersoid is organic particles, inorganic particles, or a mixture thereof, and the dispersion medium is a non-aqueous dispersion medium that is in a solid state at room temperature.

[0020] According to another aspect of the present invention, there is provided a dispersion composition comprising the solid dispersion.

[0021] The solid dispersion or dispersion composition of the present invention may be solid at room temperature. In this specification, room temperature refers to an ordinary temperature in the range of 20±5° C., and may be, for example, 25° C. Although not particularly limited, the solid dispersion of the present invention can be used as a room-temperature solid dispersion for chain extension or a room-temperature solid dispersion for curing.

[0022] The solid dispersion of the present invention includes a dispersoid dispersed in a dispersion medium. When the dispersoid contained in the solid dispersion is used in the production of a polymer or a cured product (e.g., the production of a polyurethane or a cured epoxy product), it may play a role in improving the electrical properties, thermal properties, and / or mechanical properties of the produced polymer or cured product (e.g., the polyurethane or cured epoxy product) depending on the type of dispersoid, but is not limited to this.

[0023] The dispersoid particles dispersed in the dispersion medium of the present invention may be selected from inorganic particles, organic particles, or a mixture thereof.

[0024] For example, inorganic particles can be made of iron, aluminum, chromium, nickel, cobalt, zinc, tungsten, indium, tin, palladium, zirconium, titanium, copper, silver (e.g., silver particles, silver nanowires, silver nanorods, etc.), gold (e.g., gold particles, gold nanowires, gold nanorods, etc.), platinum, alloys of two or more of these metals, or mixtures of two or more of these metals. In this case, to ensure stable removal of the inorganic particles from the medium, they can be coated with a protective agent such as alkanoic acid, fatty acid, hydroxycarboxylic acid, alicyclic carboxylic acid, aromatic carboxylic acid, alkenyl succinic anhydride, thiol, phenol derivative, amine, amphiphilic polymer, polymeric surfactant, or low molecular weight surfactant.

[0025] In addition, kaolin, clay, talc, mica, bentonite, dolomite, calcium silicate, magnesium silicate, asbestos, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, barium sulfate, aluminum sulfate, aluminum hydroxide, iron hydroxide, aluminum silicate, zirconium oxide, magnesium oxide, aluminum oxide, titanium oxide, iron oxide, zinc oxide, antimony trioxide, indium oxide, indium tin oxide, silicon carbide, silicon nitride, boron nitride, barium titanate, diatomaceous earth, carbon black, graphite, rock wool, glass wool, glass fiber, graphene, graphite, carbon fiber, carbon nanofiber or carbon nanotube (single-walled carbon nanotube, double-walled carbon nanotube or multi-walled carbon nanotube, etc.), etc. can be used as inorganic particles, and a mixture of two or more of the above-mentioned inorganic particles can be used, but is not limited thereto.

[0026] Examples of organic particles include organic pigments such as azo compounds, diazo compounds, condensed azo compounds, thioindigo compounds, indanthrone compounds, quinacridone compounds, anthraquinone compounds, benzimidazolone compounds, perylene compounds, phthalocyanine compounds, anthrapyridine compounds, and dioxazine compounds; polyethylene resins, polypropylene resins, polyester resins, nylon resins, polyamide resins, aramid resins, acrylic resins, vinylon resins, urethane resins, melamine resins, polystyrene resins, and polylactic acid resins. , acetate fiber, cellulose (e.g., nanocellulose fibrils, nanocellulose crystals, etc.), hemicellulose, lignin, chitin, chitosan, starch, polymer resins such as polyacetal, polycarbonate, polyphenylene ether, polyether ether ketone, polyether ketone, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polysulfone, polyphenylene sulfide or polyimide; or a mixture of two or more thereof can be used, but is not limited to these.

[0027] The dispersoid particles dispersed in the dispersion medium of the present invention may be crystalline or amorphous. Furthermore, the dispersoid particles dispersed in the dispersion medium of the present invention may be isotropic particles, anisotropic particles, or fibrous particles.

[0028] The dispersoid particles dispersed in the dispersion medium of the present invention may be, but are not limited to, one or more selected from the group consisting of nanocellulose fibrils, nanocellulose crystals, graphene, graphite, carbon nanotubes, carbon nanofibers, silver particles, silver nanowires, silver nanorods, gold particles, gold nanowires, gold nanorods, and combinations thereof.

[0029] In the present invention, the dispersoid particles can be obtained by a known method. There are two methods for producing dispersoid fine particles: a top-down method in which coarse particles are mechanically pulverized to make them finer, and a bottom-up method in which a plurality of unit particles are generated and then agglomerated into a cluster state to form particles. Dispersoids prepared by any method can be preferably used. Furthermore, either a wet method or a dry method may be used as a method for preparing the fine particles. Furthermore, the bottom-up method includes physical methods and chemical methods, and either method may be used.

[0030] To explain the bottom-up method in more detail, we will use an example of a method for preparing metal nanoparticles within the dispersoid particles. A typical example of a physical method within the bottom-up method is the gas evaporation method, in which bulk metal is evaporated in an inert gas and cooled and condensed by collision with the gas to produce nanoparticles. Chemical methods include the liquid-phase reduction method, in which metal ions are reduced in the presence of a liquid-phase protective agent and the resulting zero-valent metal is stabilized at nanosize, or the thermal decomposition method of metal complexes. Examples of liquid-phase reduction methods that can be used include chemical reduction, electrochemical reduction, photoreduction, and a combination of chemical reduction and photoreduction.

[0031] The dispersoid particles preferably used in the present invention can be obtained by either the top-down method or the bottom-up method, and can be produced in any environment, including an aqueous liquid phase, a non-aqueous liquid phase, and a gas phase.

[0032] The solid dispersion of the present invention includes a dispersion medium for dispersing dispersoids. When the dispersion medium is used in the production of polyurethane, it can serve to extend polyurethane chains, and when the dispersion medium is used in the curing of epoxy resins, it can serve to curing the epoxy resins.

[0033] The dispersion medium usable in the present invention may be a non-aqueous dispersion medium that is solid at room temperature but can be converted to a liquid state when heated above room temperature. By using such a non-aqueous dispersion medium, aggregation or precipitation of dispersoids can be prevented or improved when the solid dispersion is stored at room temperature, thereby achieving dispersion stabilization.

[0034] The non-aqueous dispersion medium may be one that can extend the polyurethane chain or harden the epoxy resin, and may be, for example, one or more selected from the group consisting of sugars, polyether polyols, polyester polyols, hydrogenated sugars, alkanediols, amine compounds, phenolic compounds, imidazole compounds, acid anhydride compounds, anhydrous sugar alcohols, and combinations thereof.

[0035] The sugars include monosaccharides, disaccharides, and polysaccharides, and the type of the monosaccharide is not particularly limited. Any monosaccharide that is solid at room temperature and changes to a liquid state when heated to a melting point above room temperature can be used. For example, glucose, fructose, galactose, ribose, or a mixture thereof can be used as the monosaccharide.

[0036] The type of disaccharide is not particularly limited, and any disaccharide that turns into a liquid state when heated to a melting point above room temperature can be used. For example, maltose, sucrose, lactose, or a mixture thereof can be used.

[0037] The type of polysaccharide is not particularly limited, and any polysaccharide that is solid at room temperature and changes to a liquid state when heated to a melting point above room temperature can be used. For example, oligosaccharides, cellulose, starch, glycogen, or mixtures thereof can be used.

[0038] The type of the polyether polyol is not particularly limited, and any polyether polyol can be used as long as it is solid at room temperature and changes to a liquid state when heated to a melting point above room temperature. For example, modified polypropylene glycol, polytetramethylene ether glycol (polytetrahydrofuran), or a mixture thereof can be used.

[0039] The type of polyester polyol is not particularly limited, and any polyester polyol that is solid at room temperature and changes to a liquid state when heated to a melting point above room temperature can be used. For example, butylene adipate diol, 1,6-hexane adipate diol, or a mixture thereof can be used.

[0040] The type of hydrogenated sugar is not particularly limited, and any hydrogenated sugar that is solid at room temperature and turns into a liquid state when heated to or above its melting point (which is above room temperature) can be used. For example, tetritols, pentitols, hexitols, heptitols, or mixtures thereof can be used. Preferably, hexitols, such as sorbitol, mannitol, iditol, galactitol, or mixtures thereof can be used.

[0041] The type of the alkanediol is not particularly limited, and any alkanediol can be used as long as it is solid at room temperature and changes to a liquid state when heated to a melting point above room temperature, for example, 1,4-butanediol, 1,6-hexanediol, 1,9-nonanediol, or a mixture thereof.

[0042] However, the use of chemical dispersion media can cause environmental problems. For example, when phenolic compounds are used, small amounts of free phenol can be detected after curing. Also, when amine compounds are used, odors can limit workability.

[0043] According to one embodiment, it may be preferable to use an anhydrosugar alcohol (e.g., a monoanhydrosugar alcohol, a dianhydrosugar alcohol, or a mixture thereof) as the non-aqueous dispersion medium of the present invention. In this case, there are no problems such as odor limitations on operation and elution of chemical substances after curing.

[0044] The type of the amine compound is not particularly limited, and any compound that is solid at room temperature and changes to a liquid state when heated to or above its melting point above room temperature can be used. For example, a compound selected from the group consisting of poly(ethylene glycol)diamine, (R)-(+)-1,1'-binaphthyl-2,2'-diamine, (S)-(-)-1,1'-binaphthyl-2,2'-diamine, 1,1'-binaphthyl-2,2'-diamine, 4-ethoxybenzene-1,2-diamine, diamide-dPEG®-diamine, (1R,2R)-N,N'-dimethyl-1,2-diphenylethane-1,2-diamine, N,N-bis(4-butylphenyl)benzene-1,4-diamine, or a mixture thereof can be used.

[0045] The type of the phenolic compound is not particularly limited, and any compound that is solid at room temperature and changes to a liquid state when heated to or above its melting point, which is higher than room temperature, can be used. For example, compounds selected from the group consisting of 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, 2,5-dimethylphenol, 2,3-dimethylphenol, and mixtures thereof can be used.

[0046] The type of the imidazole compound is not particularly limited, and any compound that is solid at room temperature and changes to a liquid state when heated to a melting point or higher above room temperature can be used. For example, compounds selected from the group consisting of imidazole, 1-(2-hydroxyethyl)imidazole, imidazole trifluoromethanesulfonate, imidazole-2-carboxylic acid, 4-bromo-1H-imidazole, N-benzyl-2-nitro-1H-imidazole-1-acetamide, 2-chloro-1H-imidazole, imidazole-d, imidazole-N, imidazole-2-C,N, or a mixture thereof can be used.

[0047] The type of the acid anhydride compound is not particularly limited, and any compound that is solid at room temperature and changes to a liquid state when heated to or above its melting point above room temperature can be used. For example, compounds selected from the group consisting of (2-dodecen-1-yl)succinic anhydride, maleic anhydride, succinic anhydride, phthalic anhydride, glutaric anhydride, 3,4,5,6-tetrahydrophthalic anhydride, diglycolic anhydride, itaconic anhydride, trans-1,2-cyclohexanedicarboxylic anhydride, 2,3-dimethylmaleic anhydride, 3,3-tetramethyleneglutaric anhydride, stearic anhydride, cis-aconitic anhydride, trimellitic anhydride chloride, phenylsuccinic anhydride, 3,3-dimethylglutaric anhydride, methylsuccinic anhydride, and mixtures thereof can be used.

[0048] The type of monoanhydrosugar alcohol is not particularly limited, and any monoanhydrosugar alcohol that is solid at room temperature and turns into a liquid state when heated above its melting point (e.g., above room temperature) can be used. For example, tetritan, pentitan, hexitane, heptitan, or a mixture thereof may be used. Preferably, hexitane, such as sorbitan, mannitan, iditan, galactitan, or a mixture thereof can be used.

[0049] The type of the dianhydrosugar alcohol is not particularly limited, and any dianhydrosugar alcohol can be used as long as it is solid at room temperature and turns into a liquid state when heated to or above its melting point, which is above room temperature. For example, dianhydrosugar hexitol may be used, and preferably, one selected from the group consisting of isosorbide, isomannide, isoidide, and mixtures thereof can be used.

[0050] In one embodiment, when the solid dispersion of the present invention is a room temperature solid dispersion for chain extension, one or more selected from the group consisting of anhydrous sugar alcohols, hydrogenated sugars, alkanediols, and combinations thereof can be used as the dispersion medium.

[0051] In one embodiment, when the solid dispersion of the present invention is a room-temperature solid dispersion for curing, the dispersion medium can be one or more selected from the group consisting of amine compounds, phenolic compounds, imidazole compounds, acid anhydride compounds, anhydrous sugar alcohols, and combinations thereof. Preferably, one or a mixture of two or more selected from anhydrous sugar alcohols such as monoanhydrous sugar alcohols and dianhydrous sugar alcohols can be used.

[0052] The content of the dispersoid in the solid dispersion of the present invention varies depending on the type of dispersoid used. It may be 0.0001 parts by weight or more, 0.01 parts by weight or more, 0.05 parts by weight or more, 0.1 parts by weight or more, 0.5 parts by weight or more, or 1 part by weight or more, relative to 100 parts by weight of the dispersion medium. It may be 95 parts by weight or less, 90 parts by weight or less, 85 parts by weight or less, 80 parts by weight or less, 60 parts by weight or less, or 50 parts by weight or less, for example, 0.0001 to 95 parts by weight, preferably 0.05 to 80 parts by weight. If the content of the dispersoid is too low, the strength improvement of the polyurethane to which the solid dispersion is applied may be weak, and the physical and electrical properties of the epoxy resin cured product to which the solid dispersion is applied may be reduced due to the dispersoid effect. If the content of the dispersoid is too high, the dispersoids may not be uniformly dispersed within the solid dispersion, but may be entangled with each other.

[0053] According to another aspect, the present invention provides a method for producing a solid dispersion, comprising the steps of mixing a dispersoid and a dispersion medium; and melting the dispersion medium in the mixture, wherein the dispersoid is organic particles, inorganic particles, or a mixture thereof, and the dispersion medium is a non-aqueous dispersion medium that is in a solid state at room temperature.

[0054] Although not particularly limited, in the step of melting the dispersion medium in the mixture, the mixture can be melted while removing water by applying a vacuum at a temperature equal to or higher than the melting point of the dispersion medium. Then, the melted mixture can be cooled to room temperature to obtain a solid dispersion.

[0055] In this specification, the components described in the method for producing the solid dispersion are the same as the components of the solid dispersion described above.

[0056] In yet another aspect, the present invention provides a method for producing a chain-extended polyurethane, comprising: (1) adding the solid dispersion of the present invention to a polyurethane prepolymer; and (2) reacting the mixture obtained in step (1).

[0057] In the method for producing a chain-extended polyurethane of the present invention, the polyurethane prepolymer is obtained by reacting a polyol with a polyisocyanate. For example, the polyol and polyisocyanate are thoroughly vacuum-dried at 50 to 100°C, preferably 70 to 90°C, for 12 to 36 hours, preferably 20 to 28 hours, and then added to a four-neck reactor. The polyurethane prepolymer can be produced by reacting the polyol and polyisocyanate under a nitrogen atmosphere for 0.1 to 5 hours, preferably 0.5 to 2 hours, while maintaining the temperature at 50 to 100°C, preferably 50 to 70°C.

[0058] The polyol that can be used in the present invention is not particularly limited, and polyether polyols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, random copolymers or block copolymers of ethylene oxide and propylene oxide, and random copolymers or block copolymers of ethylene oxide and butylene oxide can be used.

[0059] The polyisocyanate compound that can be used in the present invention is not particularly limited, but specific examples include 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate (TDI), 2,6-tolylene diisocyanate, 4,4'-diphenylenemethane diisocyanate (MDI), 2,4-diphenylmethane diisocyanate, 4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatobiphenyl, ... Aromatic polyisocyanate compounds such as naphthylene diisocyanate, 3,3'-dimethyl-4,4'-diisocyanatodiphenylmethane, 1,5-naphthylene diisocyanate, 4,4',4''-triphenylmethane triisocyanate, m-isocyanatophenylsulfonyl isocyanate, p-isocyanatophenylsulfonyl isocyanate; ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI ), dodecamethylene diisocyanate, 1,6,11-undecane triisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethyl caproate, bis(2-isocyanatoethyl) fumarate, bis(2-isocyanatoethyl) carbonate, 2-isocyanatoethyl-2,6-diisocyanatohexanoate, and other aliphatic polyisocyanate compounds; isophorone diisocyanate Examples of suitable polyisocyanate compounds include alicyclic polyisocyanate compounds such as cyclohexanediisocyanate (IPDI), 4,4'-dicyclohexylmethane diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI), bis(2-isocyanatoethyl)-4-cyclohexene-1,2-diethyl azodicarboxylate, 2,5-norbornane diisocyanate, and 2,6-norbornane diisocyanate. These polyisocyanate compounds can be used alone or in combination of two or more.

[0060] In the method for producing a chain-extended polyurethane of the present invention, the solid dispersion for chain extension is added to the polyurethane prepolymer, and then the mixture is placed in a coated mold, followed by curing at 80 to 200°C, preferably 100 to 150°C, for 10 to 30 hours, preferably 15 to 25 hours, to produce a chain-extended polyurethane.

[0061] In yet another aspect, the present invention provides a chain-extended polyurethane produced by reacting a polyurethane prepolymer with the solid dispersion of the present invention.

[0062] In this specification, the components described in the chain-extended polyurethane and the method for producing the chain-extended polyurethane are the same as the components of the solid dispersion.

[0063] According to yet another aspect of the present invention, there is provided an epoxy resin composition comprising: an epoxy resin; and the solid dispersion.

[0064] In one embodiment, the epoxy resin may be selected from the group consisting of, but is not limited to, bisphenol A-epichlorohydrin resin, epoxy novolac resin, cycloaliphatic epoxy resin, aliphatic epoxy resin, bicyclic epoxy resin, glycidyl ester type epoxy resin, brominated epoxy resin, bio-derived epoxy resin, epoxidized soybean oil, or combinations thereof.

[0065] In another embodiment, the epoxy resin is a novolac type epoxy resin such as a phenol novolac type epoxy resin or a cresol novolac type epoxy resin; a bisphenol type epoxy resin such as a bisphenol A type epoxy resin or a bisphenol F type epoxy resin; an aromatic glycidylamine type epoxy resin such as N,N-diglycidylaniline, N,N-diglycidyltoluidine, diaminodiphenylmethane glycidylamine, or aminophenol type glycidylamine; a hydroquinone type epoxy resin; a biphenyl type epoxy resin; a stilbene type epoxy resin; a triphenolmethane type epoxy resin; a triphenolpropane type epoxy resin; an alkyl dicyclopentadiene-modified phenol-type epoxy resins; naphthol-type epoxy resins; naphthalene-type epoxy resins; aralkyl-type epoxy resins such as phenol aralkyl-type epoxy resins having a phenylene and / or biphenylene skeleton and naphthol aralkyl-type epoxy resins having a phenylene and / or biphenylene skeleton; aliphatic epoxy resins such as vinylcyclohexene dioxide, dicyclopentadiene oxide, and alicyclic epoxies such as alicyclic diepoxy-adipates, or combinations thereof.

[0066] In yet another embodiment, the epoxy resin may be selected from the group consisting of bisphenol F type epoxy resins, cresol novolac type epoxy resins, phenol novolac type epoxy resins, biphenyl type epoxy resins, stilbene type epoxy resins, hydroquinone type epoxy resins, naphthalene skeleton type epoxy resins, tetraphenylolethane type epoxy resins, diphenyl phosphate (DPP) type epoxy resins, trishydroxyphenylmethane type epoxy resins, dicyclopentadiene phenol type epoxy resins, diglycidyl ether of bisphenol A ethylene oxide adduct, diglycidyl ether of bisphenol A propylene oxide adduct, diglycidyl ether of bisphenol A, phenyl glycidyl ether, cresyl glycidyl ether, and other glycidyl ethers having one epoxy group, hydrogenated epoxy resins of these epoxy resins, or combinations thereof, but is not limited to these.

[0067] In the epoxy resin composition of the present invention, the content of the epoxy resin and the solid dispersion is, for example, an equivalent ratio of the solid dispersion to the epoxy resin (equivalent of solid dispersion / equivalent of epoxy resin) in the range of 0.25 to 1.75, more specifically, in the range of 0.75 to 1.25, and even more specifically, in the range of 0.95 to 1.05. If the equivalent of the solid dispersion relative to the equivalent of the epoxy resin is too low, problems may arise such as a decrease in mechanical strength and a decrease in physical properties related to thermal and adhesive strength. Conversely, if the equivalent of the solid dispersion relative to the equivalent of the epoxy resin is too high, problems may arise such as a decrease in physical properties in terms of mechanical strength, thermal and adhesive strength.

[0068] For the purpose of curing acceleration, the epoxy resin composition of the present invention may further contain a curing catalyst.

[0069] Examples of the curing catalyst that can be used in the present invention include amine compounds (e.g., tertiary amines) such as benzyldimethylamine, tris(dimethylaminomethyl)phenol, and dimethylcyclohexylamine; imidazole compounds such as 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-ethyl-4-methylimidazole, and 1-benzyl-2-methylimidazole; organic phosphorus compounds such as triphenylphosphine and triphenyl phosphite; quaternary phosphonium salts such as tetraphenylphosphonium bromide and tetra-n-butylphosphonium bromide; diazabicycloalkenes such as 1,8-diazabicyclo[5.4.0]undecene-7 and organic salts thereof; zinc octoate, tin octoate, or aluminum octoate. quaternary ammonium salts such as tetraethylammonium bromide and tetrabutylammonium bromide; boron compounds such as boron trifluoride and triphenylborate; metal halides such as zinc chloride and stannic chloride; latent curing catalysts (for example, dicyandiamide, high-melting point dispersed latent amine adducts obtained by adding amine to epoxy resins, etc.; microencapsulated latent catalysts obtained by coating the surface of imidazole-, phosphorus-, or phosphine-based accelerators with a polymer; amine salt-type latent catalysts; high-temperature dissociation type thermal cationic polymerization latent catalysts such as Lewis acid salts and Bronsted acid salts), or combinations thereof, but are not limited thereto.

[0070] In one embodiment, the curing catalyst may be selected from the group consisting of an amine compound, an imidazole compound, an organic phosphorus compound, or a combination thereof.

[0071] When the epoxy resin composition of the present invention contains a curing catalyst, the amount used may be, but is not limited to, 0.01 to 1.0 parts by weight, more specifically 0.05 to 0.5 parts by weight, and even more specifically 0.08 to 0.2 parts by weight, per 100 parts by weight of the epoxy resin and solid dispersion combined. If the amount of curing catalyst used is too small, the curing reaction of the epoxy resin may not proceed sufficiently, resulting in reduced mechanical and thermal properties. Conversely, if the amount of curing catalyst used is too large, the curing reaction may slow down even during storage of the epoxy resin composition, potentially resulting in increased viscosity.

[0072] The epoxy resin composition of the present invention may further contain, if necessary, one or more additive components that are commonly used in epoxy resin compositions.

[0073] Such additive components may be selected from the group consisting of, for example, antioxidants, UV absorbers, fillers, resin modifiers, silane coupling agents, diluents, colorants, antifoaming agents, dispersants, viscosity modifiers, gloss modifiers, wetting agents, conductivity imparting agents, and combinations thereof.

[0074] The antioxidant can be used to further improve the heat resistance stability of the resulting cured product and is not particularly limited. For example, an antioxidant selected from the group consisting of phenol-based antioxidants (e.g., dibutylhydroxytoluene), sulfur-based antioxidants (e.g., mercaptopropionic acid derivatives), phosphorus-based antioxidants (e.g., 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide), or combinations thereof can be used. The content of the antioxidant in the composition may be 0.01 to 10 parts by weight, 0.05 to 5 parts by weight, or 0.1 to 3 parts by weight, per 100 parts by weight of the epoxy resin and solid dispersion combined.

[0075] The UV absorber is not particularly limited, and may be selected from the group consisting of, for example, benzotriazole UV absorbers such as TINUBIN P and TINUVIN 234, manufactured by BASF Japan Ltd.; triazine UV absorbers such as TINUVIN 1577ED; hindered amine UV absorbers such as CHIMASSOLV 2020FDL; and combinations thereof. The content of the UV absorber in the composition may be 0.01 to 10 parts by weight, 0.05 to 5 parts by weight, or 0.1 to 3 parts by weight, per 100 parts by weight of the epoxy resin and solid dispersion combined.

[0076] These fillers are primarily used in epoxy resins or curing agents to improve the mechanical properties of the cured product. Generally, increasing the amount of filler added improves the mechanical properties. Inorganic fillers include extenders such as talc, sand, silica, and calcium carbonate; reinforcing fillers such as mica, quartz, and glass fiber; and fillers with specialized uses such as quartz powder, graphite, alumina, and aerosil (to impart thixotropy). Metallic fillers include aluminum, aluminum oxide, iron, iron oxide, and copper, which contribute to thermal expansion coefficient, abrasion resistance, thermal conductivity, and adhesion; antimony oxide (SB2O3), which imparts flame retardancy; and barium titanate. Organic fillers include lightweight fillers such as fine plastic spheres (phenolic resin, urea resin, etc.). Reinforcing fillers such as various glass fibers and synthetic fiber cloths can be used in the broad sense of fillers in the production of laminates. Fine particles with a large surface area are used to give the resin thixotropy (a property that allows the resin to remain liquid when flowing and solid when stationary, preventing the resin from spilling or being lost when impregnated onto a vertical surface by immersion or when hardening). For example, colloidal silica (Aerosil) or bentonite-based clays are used.

[0077] In one embodiment, the filler is not particularly limited. For example, a filler selected from the group consisting of glass fiber, carbon fiber, titanium oxide, alumina, talc, mica, aluminum hydroxide, or a combination thereof can be used. The content of the filler in the composition may be 0.01 to 80 parts by weight, 0.01 to 50 parts by weight, or 0.1 to 20 parts by weight, based on 100 parts by weight of the epoxy resin and the solid dispersion combined.

[0078] The resin modifier is not particularly limited. Examples include flexibility-imparting agents such as polypropylene glycidyl ether, polymerized fatty acid polyglycidyl ether, polypropylene glycol, and urethane prepolymer. The content of the resin modifier in the composition may be 0.01 to 80 parts by weight, 0.01 to 50 parts by weight, or 0.1 to 20 parts by weight, based on 100 parts by weight of the epoxy resin and solid dispersion combined.

[0079] The silane coupling agent is not particularly limited. Examples include chloropropyltrimethoxysilane, vinyltrichlorosilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, etc. The content of the silane coupling agent in the composition may be 0.01 to 20 parts by weight, 0.05 to 10 parts by weight, or 0.1 to 5 parts by weight, based on 100 parts by weight of the epoxy resin and the solid dispersion combined.

[0080] Diluents are added to epoxy resins and curing agents primarily to reduce viscosity. They also improve fluidity, defoaming, and penetration into parts, or allow for the effective addition of fillers. Unlike solvents, diluents generally do not volatilize and remain in the cured product after curing. Diluents are classified as reactive and non-reactive. Reactive diluents contain one or more epoxy groups and participate in the reaction, thereby incorporating them into the crosslinking structure of the cured product. Non-reactive diluents are simply physically mixed and dispersed in the cured product. Commonly used reactive diluents include butyl glycidyl ether (BGE), phenyl glycidyl ether (PGE), aliphatic glycidyl ethers (C12-C14), modified t-carboxyl glycidyl esters, etc. Commonly used non-reactive diluents include dibutyl phthalate (DBP), dioctyl phthalate (DOP), nonylphenol, and Hysol.

[0081] In one embodiment, the diluent is not particularly limited, and examples thereof include n-butyl glycidyl ether, phenyl glycidyl ether, glycidyl methacrylate, vinylcyclohexene dioxide, diglycidyl aniline, glycerin triglycidyl ether, and combinations thereof. The content of the diluent in the composition may be 0.01 to 80 parts by weight, 0.01 to 50 parts by weight, or 0.1 to 20 parts by weight, based on 100 parts by weight of the epoxy resin and the solid dispersion combined.

[0082] Pigments or dyes are used as colorants to add color to resins. Commonly used pigments include titanium dioxide, cadmium red, shiny green, carbon black, chrome green, chrome yellow, navy blue, shiny blue, etc.

[0083] In addition, various additives can be used, such as antifoaming agents and defoaming agents for removing bubbles from the resin, dispersants for improving the dispersion effect between the resin and the pigment, wetting agents for improving adhesion between epoxy resins, viscosity modifiers, gloss modifiers for adjusting the gloss of the resin, additives for improving adhesive strength, and additives for imparting electrical properties.

[0084] The method for curing the epoxy resin composition of the present invention is not particularly limited, and for example, conventionally known curing devices such as a sealed curing oven, a tunnel oven capable of continuous curing, etc. The heating method used for the curing is also not particularly limited, and for example, conventionally known methods such as hot air circulation, infrared heating, and high-frequency heating can be used.

[0085] The curing temperature and curing time may be in the range of 80°C to 250°C and 30 seconds to 10 hours. In one embodiment, the composition can be pre-cured at 80°C to 120°C for 0.5 to 5 hours, and then post-cured at 120°C to 180°C for 0.1 to 5 hours. In one embodiment, the composition can be cured for a short time at 150°C to 250°C for 30 seconds to 30 minutes.

[0086] According to yet another aspect of the present invention, there is provided a method for producing an epoxy resin composition, comprising the step of mixing an epoxy resin and the solid dispersion.

[0087] According to yet another aspect of the present invention, there is provided a cured product obtained by curing the epoxy resin composition.

[0088] According to yet another aspect of the present invention, there is provided a molded article comprising the cured product. [Example]

[0089] The present invention will be explained in more detail through the following examples and comparative examples, however, the scope of the present invention is not limited thereby in any way.

[0090] [Example] 1. Preparation of solid dispersion for chain extension and chain-extended polyurethane <Production of solid dispersion for chain extension> Example 1-A1: Solid dispersion containing nanocellulose fibrils and anhydrosugar alcohol 100 g of isosorbide (manufactured by Samyang Co., Ltd.) and 100 g of an aqueous solution (KB101; manufactured by Asia Nano Cellulose Co., Ltd.) in which nanocellulose fibrils were dispersed at 1 wt% were added to a rotary evaporator and mixed uniformly. The mixture was then melted at a temperature of 80°C, above the melting point of isosorbide, while removing water under vacuum. The molten mixture was then cooled to room temperature to produce isosorbide (solid dispersion) in which nanocellulose fibrils were dispersed.

[0091] Example 1-A2: Solid dispersion containing nanocellulose fibrils and hydrogenated sugars 100 g of sorbitol (SAMYANG) and 100 g of an aqueous solution (KB101; Asia Nano Cellulose) in which nanocellulose fibrils were dispersed at 1 wt% were added to a rotary evaporator and mixed uniformly. The mixture was then melted at a temperature of 100°C, above the melting point of sorbitol, while removing water under vacuum. The molten mixture was then cooled to room temperature to produce sorbitol (solid dispersion) in which nanocellulose fibrils were dispersed.

[0092] Example 1-A3: Solid dispersion containing nanocellulose fibrils and alkanediol 100 g of 1,4-butanediol (Sigma-Aldrich) and 100 g of an aqueous solution (KB101; Asia Nano Cellulose) containing a 1 wt% dispersion of nanocellulose fibrils were added to a rotary evaporator and mixed uniformly. The mixture was then melted at a temperature of 40°C, above the melting point of 1,4-butanediol, while removing water under vacuum. The molten mixture was then cooled to room temperature to produce 1,4-butanediol (solid dispersion) containing dispersed nanocellulose fibrils.

[0093] Example 1-A4: Solid dispersion containing graphene and anhydrosugar alcohol 100 g of isosorbide (manufactured by Samyang) and 100 g of an aqueous solution (WDG; manufactured by MExplorer) in which graphene was dispersed at 1.5 mg / mL were added to a rotary evaporator and mixed uniformly. The mixture was then melted at a temperature of 80°C, which is higher than the melting point of isosorbide, while removing water under vacuum. The molten mixture was then cooled to room temperature to produce graphene-dispersed isosorbide (solid dispersion).

[0094] Example 1-A5: Solid dispersion containing graphene and hydrogenated sugar 100 g of sorbitol (manufactured by Samyang) and 100 g of an aqueous solution (WDG; manufactured by MExplorer) in which graphene was dispersed at 1.5 mg / mL were added to a rotary evaporator and mixed uniformly. The mixture was then melted at a temperature of 100°C, above the melting point of sorbitol, while removing water under vacuum. The molten mixture was then cooled to room temperature to produce graphene-dispersed sorbitol (solid dispersion).

[0095] Example 1-A6: Solid dispersion containing graphene and alkanediol 100 g of 1,4-butanediol (Sigma-Aldrich) and 100 g of an aqueous solution (WDG; MExplorer) in which graphene was dispersed at 1.5 mg / mL were added to a rotary evaporator and mixed uniformly. The mixture was then melted at a temperature of 40°C, above the melting point of 1,4-butanediol, while removing water under vacuum. The molten mixture was then cooled to room temperature to produce 1,4-butanediol in which graphene was dispersed (solid dispersion).

[0096] Comparative Example 1-A1: Liquid dispersion containing nanocellulose fibrils and polypropylene glycol 100 g of polypropylene glycol (PPG-3000; manufactured by Kumho Petrochemical Co., Ltd.) in a liquid state at room temperature and 100 g of an aqueous solution (KB101; manufactured by Asia Nano Cellulose Co., Ltd.) in which nanocellulose fibrils were dispersed at 1 wt% were added to a rotary evaporator and mixed uniformly. After that, a vacuum was applied to remove the water, producing polypropylene glycol (liquid dispersion) in which nanocellulose fibrils were dispersed.

[0097] Comparative Example 1-A2: Liquid dispersion containing graphene and polypropylene glycol 100 g of polypropylene glycol (PPG-3000; manufactured by Kumho Petrochemical Co., Ltd.) in a liquid state at room temperature and 100 g of an aqueous solution (WDG; manufactured by MExplorer Co., Ltd.) in which graphene was dispersed at 1.5 mg / mL were added to a rotary evaporator and mixed uniformly. After that, a vacuum was applied to remove the water, and a polypropylene glycol (liquid dispersion) in which graphene was dispersed was produced.

[0098] <Production of chain-extended polyurethane> Example 1-B1: Preparation of polyurethane using a solid dispersion containing nanocellulose fibrils and anhydrosugar alcohol 100 g (0.1 mol) of poly(tetramethylene ether glycol) (PTMEG, molecular weight: 1,000) thoroughly dried in a vacuum at 80°C for 24 hours and 50.5 g (0.2 mol) of 4,4'-methylenediphenyl diisocyanate (MDI) were added to a four-neck reactor and reacted for 1 hour at 60°C under a nitrogen atmosphere to produce a polyurethane prepolymer. Next, the NCO% of the polyurethane prepolymer was measured. When it reached the theoretical NCO%, 14.6 g of isosorbide dispersed with nanocellulose fibrils (prepared in Example 1-A1) was added as a chain extender. The mixture was poured into a coated mold and cured at 110°C for 16 hours to produce a chain-extended polyurethane.

[0099] Example 1-B2: Preparation of polyurethane using solid dispersion containing graphene and anhydrosugar alcohol A chain-extended polyurethane was prepared in the same manner as in Example 1-B1, except that the dispersion prepared in Example 1-A4 (isosorbide dispersed with graphene) was used as the chain extender instead of the dispersion prepared in Example 1-A1 (isosorbide dispersed with nanocellulose fibrils).

[0100] Example 1-B3: Preparation of polyurethane using solid dispersion containing nanocellulose fibrils and alkanediol A chain-extended polyurethane was prepared in the same manner as in Example 1-B1, except that the dispersion prepared in Example 1-A3 (1,4-butanediol in which nanocellulose fibrils are dispersed) was used as the chain extender instead of the dispersion prepared in Example 1-A1 (isosorbide in which nanocellulose fibrils are dispersed).

[0101] Example 1-B4: Preparation of polyurethane using solid dispersion containing graphene and alkanediol A chain-extended polyurethane was prepared in the same manner as in Example 1-B1, except that the dispersion prepared in Example 1-A6 (1,4-butanediol in which graphene is dispersed) was used as the chain extender instead of the dispersion prepared in Example 1-A1 (isosorbide in which nanocellulose fibrils are dispersed).

[0102] Example 1-B5: Preparation of polyurethane using solid dispersion containing nanocellulose fibrils and hydrogenated sugar A chain-extended polyurethane was prepared in the same manner as in Example 1-B1, except that the dispersion prepared in Example 1-A2 (sorbitol in which nanocellulose fibrils are dispersed) was used as the chain extender instead of the dispersion prepared in Example 1-A1 (isosorbide in which nanocellulose fibrils are dispersed).

[0103] Example 1-B6: Preparation of polyurethane using solid dispersion containing graphene and hydrogenated sugar A chain-extended polyurethane was prepared in the same manner as in Example 1-B1, except that the dispersion prepared in Example 1-A5 (graphene-dispersed sorbitol) was used as the chain extender instead of the dispersion prepared in Example 1-A1 (nanocellulose fibrils-dispersed isosorbide).

[0104] Comparative Example 1-B1: Preparation of polyurethane using anhydrosugar alcohol as a chain extender A chain-extended polyurethane was prepared in the same manner as in Example 1-B1, except that isosorbide was used as the chain extender instead of the dispersion (isosorbide in which nanocellulose fibrils are dispersed) prepared in Example 1-A1.

[0105] Comparative Example 1-B2: Preparation of polyurethane containing nanocellulose fibrils using anhydrosugar alcohol as a chain extender 100 g (0.1 mol) of poly(tetramethylene ether glycol) (PTMEG, molecular weight: 1,000) thoroughly dried at 80 °C for 24 hours and 0.146 g of nanocellulose fibrils were added to a four-neck reactor and slowly stirred under a nitrogen atmosphere. Next, 50.5 g (0.2 mol) of 4,4'-methylenediphenyl diisocyanate (MDI) was added to the four-neck reactor under a nitrogen atmosphere and reacted for 1 hour while maintaining the temperature at 60 °C to produce a polyurethane prepolymer. The NCO% of the polyurethane prepolymer was then measured, and when it reached the theoretical NCO%, 14.6 g of isosorbide was added as a chain extender. The mixture was placed in a coated mold and cured at 110 °C for 16 hours to produce a chain-extended polyurethane.

[0106] Comparative Example 1-B3: Preparation of polyurethane containing graphene using anhydrous sugar alcohol as a chain extender A chain-extended polyurethane was prepared in the same manner as in Comparative Example 1-B2, except that 0.146 g of graphene was added instead of 0.146 g of nanocellulose fibrils.

[0107] Comparative Example 1-B4: Preparation of polyurethane using a liquid dispersion containing nanocellulose fibrils and polypropylene glycol A chain-extended polyurethane was prepared in the same manner as in Example 1-B1, except that the dispersion prepared in Comparative Example 1-A1 (polypropylene glycol in which nanocellulose fibrils are dispersed) was used as the chain extender instead of the dispersion prepared in Example 1-A1 (isosorbide in which nanocellulose fibrils are dispersed).

[0108] Comparative Example 1-B5: Preparation of polyurethane using a liquid dispersion containing graphene and polypropylene glycol A chain-extended polyurethane was prepared in the same manner as in Example 1-B1, except that the dispersion prepared in Comparative Example 1-A2 (graphene-dispersed polypropylene glycol) was used as the chain extender instead of the dispersion prepared in Example 1-A1 (nanocellulose fibrils-dispersed isosorbide).

[0109] <Physical property measurement method> [Redispersibility evaluation method] The dispersions prepared in Examples 1-A1 to 1-A6 and Comparative Examples 1-A1 to 1-A2 were stored at room temperature for 24 hours, and then 10 g of each dispersion was placed in a vial containing 15 mL of water and stirred for 1 hour using a magnetic bar to prepare samples. The degree of dispersion of the dispersoids in the prepared samples was then observed with the naked eye, and the results are shown in Table 1 below. ○○: The dispersion state of the dispersoid is the same as that immediately after the production of the dispersion composition. ○: The dispersion state of the dispersoid is such that small lumps are floating compared to the state immediately after the preparation of the dispersion composition. ×: The dispersed state of the dispersoid is such that large lumps are floating compared to the state immediately after the preparation of the dispersion composition. ××: Dispersoids are not dissolved in water

[0110] [Storage stability evaluation method] Samples were prepared in the same manner as in the redispersibility evaluation method, and then each sample was stored at room temperature for 1 hour, after which the degree of aggregation and precipitation of the dispersoids was visually observed. The results are shown in Table 1 below. ○○: Dispersoids do not aggregate or precipitate ○: A small amount of dispersoids aggregates and precipitates ×: Most of the dispersoids aggregate and precipitate

[0111] [Method for evaluating tensile stress] The tensile stress of the polyurethane specimens prepared in Examples 1-B1 to 1-B6 and Comparative Examples 1-B1 to 1-B5 was measured using a universal tensile tester in accordance with ASTM D412, and the results are shown in Table 2 below.

[0112] [Table 1]

[0113] [Table 2]

[0114] As shown in Table 1, in the case of Examples 1-A1 to 1-A6 of the present invention, the dispersions exist in a solid state at room temperature and have excellent storage stability, making them easy to store for long periods of time and also demonstrating excellent redispersibility. However, in the case of dispersions in which the dispersion medium was in a liquid state at room temperature (Comparative Examples 1-A1 and 1-A2), the dispersoids became entangled with each other and aggregated into small lumps, resulting in poor redispersibility. Furthermore, aggregation and precipitation occurred during long-term storage at room temperature, confirming poor storage stability. Furthermore, as shown in Table 2, in the case of Examples 1-B1 to 1-B6 of the present invention, it was confirmed that the tensile stress of the chain-extended polyurethane was significantly improved to 30 MPa or more by using a dispersion in which the dispersoid (nanocellulose fibrils or graphene) was uniformly dispersed. However, in Comparative Example 1-B1, in which only anhydrous sugar alcohol was used as a chain extender, the tensile strength was significantly inferior to that of the Examples. In Comparative Examples 1-B2 and 1-B3, in which only anhydrous sugar alcohol was used as a chain extender and an additive (nanocellulose fibrils or graphene) was mixed with a prepolymer polyol, the additive was not uniformly dispersed, and aggregation occurred in the polyurethane to which this was applied, making it impossible to measure the tensile strength. Furthermore, in Comparative Examples 1-B4 and 1-B5, in which dispersions in a liquid state at room temperature were used, the dispersoids became entangled, aggregated into small lumps, and precipitated. Therefore, an additional stirring step had to be carried out before using the sample. When the sample was stored for a long period of time, the dispersoids aggregated, making it difficult to disperse even with stirring.

[0115] 2. Preparation of curable solid dispersion and epoxy resin composition <Production of solid dispersion for curing> Example 2-A1: Solid dispersion for hardening containing nanocellulose fibrils and anhydrosugar alcohol 100 g of isosorbide (manufactured by Samyang Co., Ltd.) as a dispersion medium and 100 g of an aqueous solution (KB101; manufactured by Asia Nano Cellulose Co., Ltd.) containing 1 wt% nanocellulose fibrils were added to a rotary evaporator and mixed uniformly. The mixture was then melted at a temperature of 80°C, above the melting point of isosorbide, while removing water under vacuum. The molten mixture was then cooled to room temperature to produce isosorbide (solid dispersion for hardening) in which nanocellulose fibrils were dispersed.

[0116] Example 2-A2: Solid dispersion for hardening containing graphene and anhydrosugar alcohol 100 g of isosorbide (manufactured by SAMYANG) as a dispersion medium and 100 g of an aqueous solution (WDG; manufactured by MExplorer) in which graphene was dispersed at 1.5 mg / mL were added to a rotary evaporator and mixed uniformly. The mixture was then melted at a temperature of 80°C, which is higher than the melting point of isosorbide, while removing water under vacuum. The melted mixture was then cooled to room temperature to produce isosorbide (solid dispersion for curing) in which graphene was dispersed.

[0117] Example 2-A3: Solid dispersion for hardening containing nanocellulose fibrils and an amine compound 10 g of (1R,2R)-N,N'-dimethyl-1,2-diphenylethane-1,2-diamine (Sigma-Aldrich) as a dispersion medium and 10 g of an aqueous solution (KB101; Asia Nano Cellulose) containing 1 wt% nanocellulose fibrils were added to a rotary evaporator and mixed uniformly. The mixture was then melted under vacuum at 80 °C, above the melting point of (1R,2R)-N,N'-dimethyl-1,2-diphenylethane-1,2-diamine while removing water. The molten mixture was then cooled to room temperature to produce (1R,2R)-N,N'-dimethyl-1,2-diphenylethane-1,2-diamine (solid dispersion for curing) containing dispersed nanocellulose fibrils.

[0118] Example 2-A4: Curable solid dispersion containing graphene and an amine compound 10 g of (1R,2R)-N,N'-dimethyl-1,2-diphenylethane-1,2-diamine (Sigma-Aldrich) as a dispersion medium and 10 g of an aqueous solution (WDG; MExplorer) containing graphene dispersed at 1.5 mg / mL were added to a rotary evaporator and mixed uniformly. The mixture was then melted under vacuum at 80°C, above the melting point of (1R,2R)-N,N'-dimethyl-1,2-diphenylethane-1,2-diamine while removing water. The molten mixture was then cooled to room temperature to produce (1R,2R)-N,N'-dimethyl-1,2-diphenylethane-1,2-diamine (solid dispersion for curing) containing dispersed graphene.

[0119] Example 2-A5: Solid dispersion for hardening containing nanocellulose fibrils and phenolic compounds 10 g of 2,3-xylenol (Sigma-Aldrich) as a dispersion medium and 10 g of an aqueous solution (KB101; Asia Nano Cellulose) in which nanocellulose fibrils were dispersed at 1 wt% were added to a rotary evaporator and mixed uniformly. The mixture was then melted at a temperature of 80°C, above the melting point of 2,3-xylenol, while removing water under vacuum. The molten mixture was then cooled to room temperature to produce 2,3-xylenol (solid dispersion for hardening) in which nanocellulose fibrils were dispersed.

[0120] Example 2-A6: Curable solid dispersion containing graphene and a phenolic compound 10 g of 2,3-xylenol (Sigma-Aldrich) as a dispersion medium and 10 g of an aqueous solution (WDG; MExplorer) in which graphene was dispersed at 1.5 mg / mL were added to a rotary evaporator and mixed uniformly. The mixture was then melted at a temperature of 80°C, which is higher than the melting point of 2,3-xylenol, while removing water under vacuum. The molten mixture was then cooled to room temperature to produce 2,3-xylenol (solid dispersion for curing) in which graphene was dispersed.

[0121] Example 2-A7: Solid dispersion for hardening containing nanocellulose fibrils and an imidazole-based compound 10 g of imidazole (Sigma-Aldrich) as a dispersion medium and 10 g of an aqueous solution (KB101; Asia Nano Cellulose) in which nanocellulose fibrils were dispersed at 1 wt% were added to a rotary evaporator and mixed uniformly. The mixture was then melted at a temperature of 100°C, above the melting point of imidazole, while removing water under vacuum. The molten mixture was then cooled to room temperature to produce imidazole (solid dispersion for hardening) in which nanocellulose fibrils were dispersed.

[0122] Example 2-A8: Curable solid dispersion containing graphene and an imidazole-based compound 10 g of imidazole (Sigma-Aldrich) as a dispersion medium and 100 g of an aqueous solution (WDG; MExplorer) in which graphene was dispersed at 1.5 mg / mL were added to a rotary evaporator and mixed uniformly. The mixture was then melted at a temperature of 100°C, above the melting point of imidazole, while removing water under vacuum. The molten mixture was then cooled to room temperature to produce imidazole (solid dispersion for curing) in which graphene was dispersed.

[0123] Example 2-A9: Solid dispersion for hardening containing nanocellulose fibrils and an acid anhydride compound 100 g of maleic anhydride (Sigma-Aldrich) as a dispersion medium and 100 g of an aqueous solution (KB101; Asia Nano Cellulose) in which nanocellulose fibrils were dispersed at 1 wt% were added to a rotary evaporator and mixed uniformly. The mixture was then melted at a temperature of 80°C, above the melting point of maleic anhydride, while removing water under vacuum. The molten mixture was then cooled to room temperature to produce maleic anhydride (solid dispersion for hardening) in which nanocellulose fibrils were dispersed.

[0124] Example 2-A10: Curable solid dispersion containing graphene and an acid anhydride compound 100 g of maleic anhydride (Sigma-Aldrich) as a dispersion medium and 100 g of an aqueous solution (WDG; MExplorer) in which graphene was dispersed at 1.5 mg / mL were added to a rotary evaporator and mixed uniformly. The mixture was then melted at a temperature of 80°C, above the melting point of maleic anhydride, while removing water under vacuum. The molten mixture was then cooled to room temperature to produce maleic anhydride (solid dispersion for curing) in which graphene was dispersed.

[0125] Comparative Example 2-A1: Nanocellulose fibrils and a hardener containing polypropylene glycol 100 g of polypropylene glycol (PPG-3000; manufactured by Kumho Petrochemical Co., Ltd.) in a liquid state at room temperature and 100 g of an aqueous solution (KB101; manufactured by Asia Nano Cellulose Co., Ltd.) in which nanocellulose fibrils were dispersed at 1 wt% were added to a rotary evaporator and mixed uniformly. After that, a vacuum was applied to remove the water, producing polypropylene glycol (liquid hardener) in which nanocellulose fibrils were dispersed.

[0126] Comparative Example 2-A2: Curing agent containing graphene and polypropylene glycol 100 g of polypropylene glycol (PPG-3000; manufactured by Kumho Petrochemical Co., Ltd.) in a liquid state at room temperature and 100 g of an aqueous solution (WDG; manufactured by MExplorer Co., Ltd.) in which graphene was dispersed at 1.5 mg / mL were added to a rotary evaporator and mixed uniformly. After that, a vacuum was applied to remove the water, and polypropylene glycol (liquid curing agent) in which graphene was dispersed was produced.

[0127] <Production of Epoxy Resin Composition> Example 2-B1: Preparation of an epoxy resin composition using a curing solid dispersion containing nanocellulose fibrils and anhydrosugar alcohol An epoxy resin composition was prepared by mixing a diglycidyl ether of bisphenol A (DGEBA)-based bifunctional epoxy resin (YD-128; manufactured by KUKDO CHEMICAL Co., Ltd., epoxy equivalent (EEW): 187 g / eq, 1 equivalent) with the nanocellulose fibril-dispersed isosorbide (manufactured by SAMYANG Co., Ltd., hydroxy equivalent (HEW): 73 g / eq, 1 equivalent) prepared in Example 2-A1, and adding 0.1 parts by weight of N,N-dimethylbutylamine as a catalyst to 100 parts by weight of the mixture. The epoxy resin composition was then placed in a mold coated with Teflon film and cured in stages at 100°C for 1 hour, 120°C for 1 hour, 150°C for 3 hours, and 180°C for 1 hour.

[0128] Example 2-B2: Preparation of epoxy resin composition using a curing solid dispersion containing graphene and anhydrosugar alcohol An epoxy resin composition was prepared and cured in the same manner as in Example 2-B1, except that the graphene-dispersed isosorbide prepared in Example 2-A2 (manufactured by Samyang Co., Ltd., hydroxy equivalent (HEW): 73 g / eq, 1 equivalent) prepared in Example 2-A2 was used as the curing agent instead of the nanocellulose fibril-dispersed isosorbide prepared in Example 2-A1.

[0129] Example 2-B3: Preparation of an epoxy resin composition using a curing solid dispersion containing nanocellulose fibrils and an amine compound An epoxy resin composition was prepared and cured in the same manner as in Example 2-B1, except that (1R,2R)-N,N'-dimethyl-1,2-diphenylethane-1,2-diamine in which nanocellulose fibrils prepared in Example 2-A3 were dispersed was used as the curing agent instead of the isosorbide in which nanocellulose fibrils prepared in Example 2-A1 were dispersed.

[0130] Example 2-B4: Preparation of epoxy resin composition using a curing solid dispersion containing graphene and an amine compound An epoxy resin composition was prepared and cured in the same manner as in Example 2-B1, except that the graphene-dispersed (1R,2R)-N,N'-dimethyl-1,2-diphenylethane-1,2-diamine prepared in Example 2-A4 was used as the curing agent instead of the nanocellulose fibril-dispersed isosorbide prepared in Example 2-A1.

[0131] Example 2-B5: Preparation of an epoxy resin composition using a curing solid dispersion containing nanocellulose fibrils and a phenolic compound An epoxy resin composition was prepared and cured in the same manner as in Example 2-B1, except that the 2,3-xylenol in which nanocellulose fibrils are dispersed prepared in Example 2-A5 was used as the curing agent instead of the isosorbide in which nanocellulose fibrils are dispersed prepared in Example 2-A1.

[0132] Example 2-B6: Preparation of epoxy resin composition using a curing solid dispersion containing graphene and a phenolic compound An epoxy resin composition was prepared and cured in the same manner as in Example 2-B1, except that the graphene-dispersed 2,3-xylenol prepared in Example 2-A6 was used as the curing agent instead of the nanocellulose fibril-dispersed isosorbide prepared in Example 2-A1.

[0133] Example 2-B7: Preparation of an epoxy resin composition using a curing solid dispersion containing nanocellulose fibrils and an imidazole-based compound An epoxy resin composition was prepared and cured in the same manner as in Example 2-B1, except that the imidazole in which nanocellulose fibrils are dispersed prepared in Example 2-A7 was used as the curing agent instead of the isosorbide in which nanocellulose fibrils are dispersed prepared in Example 2-A1.

[0134] Example 2-B8: Preparation of epoxy resin composition using a curing solid dispersion containing graphene and an imidazole-based compound An epoxy resin composition was prepared and cured in the same manner as in Example 2-B1, except that the graphene-dispersed imidazole prepared in Example 2-A8 was used as the curing agent instead of the nanocellulose fibril-dispersed isosorbide prepared in Example 2-A1.

[0135] Example 2-B9: Preparation of an epoxy resin composition using a curing solid dispersion containing nanocellulose fibrils and an acid anhydride compound An epoxy resin composition was prepared and cured in the same manner as in Example 2-B1, except that the maleic anhydride in which nanocellulose fibrils are dispersed prepared in Example 2-A9 was used as the curing agent instead of the isosorbide in which nanocellulose fibrils are dispersed prepared in Example 2-A1.

[0136] Example 2-B10: Preparation of epoxy resin composition using a curing solid dispersion containing graphene and an acid anhydride compound An epoxy resin composition was prepared and cured in the same manner as in Example 2-B1, except that the graphene-dispersed maleic anhydride prepared in Example 2-A10 was used as the curing agent instead of the nanocellulose fibrils-dispersed isosorbide prepared in Example 2-A1.

[0137] Comparative Example 2-B1: Preparation of an epoxy resin composition using an anhydrosugar alcohol as a curing agent An epoxy resin composition was prepared and cured in the same manner as in Example 2-B1, except that isosorbide (manufactured by Samyang Co., Ltd., hydroxy equivalent (HEW): 73 g / eq, 1 equivalent) was used as the curing agent instead of the isosorbide in which nanocellulose fibrils were dispersed prepared in Example 2-A1.

[0138] Comparative Example 2-B2: Preparation of an epoxy resin composition using anhydrosugar alcohol as a curing agent and adding separate nanocellulose fibrils An epoxy resin composition was prepared by mixing a bifunctional epoxy resin (YD-128; manufactured by KUKDO CHEMICAL, epoxy equivalent (EEW): 187 g / eq, 1 equivalent), isosorbide (manufactured by SAMYANG, hydroxy equivalent (HEW): 73 g / eq, 1 equivalent), and 0.73 g of nanocellulose fibrils, and adding 0.1 parts by weight of N,N-dimethylbutylamine (DMBA; manufactured by Sigma-Aldrich) as a catalyst to 100 parts by weight of the mixture. The epoxy resin composition was then placed in a mold coated with Teflon film and cured in stages at 100°C for 1 hour, 120°C for 1 hour, 150°C for 3 hours, and 180°C for 1 hour.

[0139] Comparative Example 2-B3: Preparation of an epoxy resin composition containing graphene and anhydrous sugar alcohol as a curing agent An epoxy resin composition was prepared and cured in the same manner as in Comparative Example 2-B2, except that 0.73 g of graphene was added instead of 0.73 g of nanocellulose fibrils.

[0140] Comparative Example 2-B4: Preparation of an epoxy resin composition using nanocellulose fibrils and a curing agent containing polypropylene glycol An epoxy resin composition was prepared and cured in the same manner as in Example 2-B1, except that the curing agent prepared in Comparative Example 2-A1 (polypropylene glycol with nanocellulose fibrils dispersed therein) was used instead of the curing agent prepared in Example 2-A1 (isosorbide with nanocellulose fibrils dispersed therein).

[0141] Comparative Example 2-B5: Preparation of an epoxy resin composition using a curing agent containing graphene and polypropylene glycol An epoxy resin composition was prepared and cured in the same manner as in Example 2-B1, except that the curing agent prepared in Comparative Example 2-A2 (graphene-dispersed polypropylene glycol) was used instead of the curing agent prepared in Example 2-A1 (nanocellulose fibrils-dispersed isosorbide).

[0142] <Physical property measurement method> [Redispersibility evaluation method] The solid dispersions for curing prepared in Examples 2-A1 to 2-A10 and Comparative Examples 2-A1 to 2-A2 were stored at room temperature for 24 hours, and then 10 g of each solid dispersion for curing was placed in a vial containing 15 mL of water and stirred for 1 hour using a magnetic bar to prepare a sample. The degree of dispersion of the dispersoids in the prepared sample was then observed with the naked eye, and the results are shown in Table 3 below. ○○: The dispersion state of the dispersoid is the same as that immediately after the production of the solid dispersion for curing. ○: The dispersion state of the dispersoid is such that small lumps are floating compared to the state immediately after the production of the solid dispersion for curing. ×: The dispersion state of the dispersoid is such that large lumps are floating compared to the state immediately after the production of the solid dispersion for curing. ××: Dispersoids are not dissolved in water

[0143] [Storage stability evaluation method] Samples were prepared in the same manner as described in the redispersibility evaluation method, and then each prepared sample was stored at room temperature for 1 hour, and the degree of aggregation and precipitation of the dispersoids was observed with the naked eye. The results are shown in Table 3 below. ○○: Dispersoids do not aggregate or precipitate ○: A small amount of dispersoids aggregates and precipitates ×: Most of the dispersoids aggregate and precipitate

[0144] [Method for evaluating tensile stress] The tensile stress of the cured specimens of the epoxy resin compositions prepared in Examples 2-B1 to 2-B10 and Comparative Examples 2-B1 to 2-B5 was measured using a universal tensile tester in accordance with ASTM D412. The tensile stress of each specimen was measured five times, and the average value of the five measurements is shown in Table 4 below.

[0145] [Table 3]

[0146] [Table 4]

[0147] As shown in Table 3, in the case of Examples 2-A1 to 2-A10 of the present invention, the solid dispersions for curing exist in a solid state at room temperature, and therefore have excellent storage stability. As a result, it was confirmed that they are easy to store for a long period of time and have excellent redispersibility. However, in the case of dispersions in which the dispersion medium was in a liquid state at room temperature (Comparative Examples 2-A1 and 2-A2), the dispersoids became entangled with each other, causing aggregation into small clumps. As a result, redispersibility decreased. Furthermore, aggregation and precipitation occurred during long-term storage at room temperature, confirming poor storage stability. Furthermore, as shown in Table 4, in the case of Examples 2-B1 to 2-B10 of the present invention, it was confirmed that the tensile stress of the cured product of the epoxy resin composition was significantly improved to 68 MPa or more by using a solid dispersion for curing in which the dispersoid (nanocellulose fibrils or graphene) was uniformly dispersed. However, in Comparative Example 2-B1, in which only a dispersion medium (anhydrous sugar alcohol) was used as the curing agent, the tensile stress was significantly lower than that of the Examples. In Comparative Examples 2-B2 and 2-B3, in which only a dispersion medium (anhydrous sugar alcohol) was used as the curing agent and the additive (nanocellulose fibrils or graphene) was mixed without pre-dispersion, the additive was not uniformly dispersed, and in the case of the cured product of the epoxy resin composition to which this was applied, aggregation occurred, making it impossible to measure the tensile stress itself. Furthermore, in Comparative Examples 2-B4 and 2-B5, which used liquid dispersions in which the dispersoids were dispersed but existed in a liquid state at room temperature, the dispersoids entangled with each other, aggregated into small clumps, and precipitated. Two of the five tensile stress measurements for each specimen were impossible due to aggregation, and the average tensile stress values were significantly worse than those of the Examples. Therefore, an additional stirring step was required before using the samples. When stored for a long period of time, the dispersoids aggregated, making them difficult to disperse even with stirring.

[0148] 3. Preparation of Dispersion Composition <Production of Dispersion Composition> Example 3-1: Dispersion composition containing nanocellulose fibrils and monosaccharides 100 g of glucose (manufactured by Samyang Co., Ltd.) and 100 g of an aqueous solution (KB101; manufactured by Asia Nano Cellulose Co., Ltd.) in which nanocellulose fibrils were dispersed at 1 wt% were added to a rotary evaporator and mixed uniformly. The mixture was then melted at a temperature of 150°C, above the melting point of glucose, while removing water under vacuum. The molten mixture was then cooled to room temperature to produce glucose with nanocellulose fibrils dispersed therein (solid dispersion composition).

[0149] Example 3-2: Dispersion composition containing nanocellulose fibrils and disaccharides 100 g of sucrose (manufactured by Samyang Co., Ltd.) and 100 g of an aqueous solution (KB101; manufactured by Asia Nano Cellulose Co., Ltd.) in which nanocellulose fibrils were dispersed at 1 wt% were added to a rotary evaporator and mixed uniformly. The mixture was then melted at a temperature of 190°C, above the melting point of sucrose, while removing water under vacuum. The molten mixture was then cooled to room temperature to produce sucrose (solid dispersion composition) in which nanocellulose fibrils were dispersed.

[0150] Example 3-3: Dispersion composition containing nanocellulose fibrils and polysaccharides 100 g of starch (manufactured by Samyang Co., Ltd.) and 100 g of an aqueous solution (KB101; manufactured by Asia Nano Cellulose Co., Ltd.) in which nanocellulose fibrils were dispersed at 1 wt% were added to a rotary evaporator and mixed uniformly. The mixture was then melted at a temperature of 220°C, above the melting point of the starch, while removing water under vacuum. The molten mixture was then cooled to room temperature to produce starch with nanocellulose fibrils dispersed therein (solid dispersion composition).

[0151] Examples 3-4: Dispersion composition containing nanocellulose fibrils and anhydrosugar alcohol 100 g of isosorbide (manufactured by Samyang Co., Ltd.) and 100 g of an aqueous solution (KB101; manufactured by Asia Nano Cellulose Co., Ltd.) in which nanocellulose fibrils were dispersed at 1 wt% were added to a rotary evaporator and mixed uniformly. The mixture was then melted at a temperature of 80°C, above the melting point of isosorbide, while removing water under vacuum. The molten mixture was then cooled to room temperature to produce isosorbide (solid dispersion composition) in which nanocellulose fibrils were dispersed.

[0152] Examples 3-5: Dispersion compositions containing nanocellulose fibrils and hydrogenated sugars 100 g of sorbitol (manufactured by Samyang Co., Ltd.) and 100 g of an aqueous solution (KB101; manufactured by Asia Nano Cellulose Co., Ltd.) in which nanocellulose fibrils were dispersed at 1 wt% were added to a rotary evaporator and mixed uniformly. The mixture was then melted at a temperature of 100°C, above the melting point of sorbitol, while removing water under vacuum. The molten mixture was then cooled to room temperature to produce sorbitol (solid dispersion composition) in which nanocellulose fibrils were dispersed.

[0153] Examples 3-6: Dispersion compositions containing nanocellulose fibrils and polyether polyol 100 g of polytetrahydrofuran (weight average molecular weight: 1000 g / mol, manufactured by Sigma-Aldrich) and 100 g of an aqueous solution (KB101; manufactured by Asia Nano Cellulose) in which nanocellulose fibrils were dispersed at 1 wt% were added to a rotary evaporator and mixed uniformly. The mixture was then melted at a temperature of 80°C, above the melting point of polytetrahydrofuran, while removing water under vacuum. The molten mixture was then cooled to room temperature to produce polytetrahydrofuran (solid dispersion composition) in which nanocellulose fibrils were dispersed.

[0154] Examples 3-7: Dispersion compositions containing graphene and monosaccharides 100 g of glucose (manufactured by Samyang) and 100 g of an aqueous solution (WDG; manufactured by MExplorer) in which graphene was dispersed at 1.5 mg / mL were added to a rotary evaporator and mixed uniformly. The mixture was then melted at a temperature of 150°C, which is higher than the melting point of glucose, while removing water under vacuum. The melted mixture was then cooled to room temperature to produce glucose with graphene dispersed therein (solid dispersion composition).

[0155] Examples 3-8: Dispersion compositions containing graphene and disaccharides 100 g of sucrose (manufactured by Samyang) and 100 g of an aqueous solution (WDG; manufactured by MExplorer) in which graphene was dispersed at 1.5 mg / mL were added to a rotary evaporator and mixed uniformly. The mixture was then melted at a temperature of 190°C, which is higher than the melting point of sucrose, while removing water under vacuum. The melted mixture was then cooled to room temperature to produce sucrose in which graphene was dispersed (solid dispersion composition).

[0156] Examples 3-9: Dispersion Compositions Comprising Graphene and Polysaccharides 100 g of starch (manufactured by Samyang) and 100 g of an aqueous solution (WDG; manufactured by MExplorer) in which graphene was dispersed at 1.5 mg / mL were added to a rotary evaporator and mixed uniformly. Then, the mixture was melted at a temperature of 220°C, which is higher than the melting point of the starch, while removing water under vacuum. The melted mixture was then cooled to room temperature to produce starch in which graphene was dispersed (solid dispersion composition).

[0157] Examples 3-10: Dispersion compositions containing graphene and anhydrosugar alcohol 100 g of isosorbide (manufactured by Samyang) and 100 g of an aqueous solution (WDG; manufactured by MExplorer) in which graphene was dispersed at 1.5 mg / mL were added to a rotary evaporator and mixed uniformly. The mixture was then melted at a temperature of 80°C, which is higher than the melting point of isosorbide, while removing water under vacuum. The melted mixture was then cooled to room temperature to produce isosorbide (solid dispersion composition) in which graphene was dispersed.

[0158] Examples 3-11: Dispersion Compositions Containing Graphene and Hydrogenated Sugars 100 g of sorbitol (manufactured by Samyang) and 100 g of an aqueous solution (WDG; manufactured by MExplorer) in which graphene was dispersed at 1.5 mg / mL were added to a rotary evaporator and mixed uniformly. The mixture was then melted at a temperature of 100°C, which is higher than the melting point of sorbitol, while removing water under vacuum. The melted mixture was then cooled to room temperature to produce sorbitol (solid dispersion composition) in which graphene was dispersed.

[0159] Examples 3-12: Dispersion Compositions Comprising Graphene and Polyether Polyol 100 g of polytetrahydrofuran (weight average molecular weight: 1000 g / mol; manufactured by Sigma-Aldrich) and 100 g of an aqueous solution (WDG; manufactured by MExplorer) in which graphene was dispersed at 1.5 mg / mL were added to a rotary evaporator and mixed uniformly. The mixture was then melted at a temperature of 80°C, which is higher than the melting point of polytetrahydrofuran, while removing water under vacuum. The molten mixture was then cooled to room temperature to produce polytetrahydrofuran in which graphene was dispersed (solid dispersion composition).

[0160] Comparative Example 3-1: Dispersion composition containing nanocellulose fibrils and polypropylene glycol 100 g of polypropylene glycol (PPG-3000; manufactured by Kumho Petrochemical Co., Ltd.) in a liquid state at room temperature and 100 g of an aqueous solution (KB101; manufactured by Asia Nano Cellulose Co., Ltd.) in which nanocellulose fibrils were dispersed at 1 wt% were added to a rotary evaporator and mixed uniformly. After that, a vacuum was applied to remove the water, and polypropylene glycol in which nanocellulose fibrils were dispersed (liquid dispersion composition) was produced.

[0161] Comparative Example 3-2: Dispersion composition containing graphene and polypropylene glycol 100 g of polypropylene glycol (PPG-3000; manufactured by Kumho Petrochemical Co., Ltd.) in a liquid state at room temperature and 100 g of an aqueous solution (WDG; manufactured by MExplorer Co., Ltd.) in which graphene was dispersed at 1.5 mg / mL were added to a rotary evaporator and mixed uniformly. Then, a vacuum was applied to remove water, producing polypropylene glycol (liquid dispersion composition) in which graphene was dispersed.

[0162] The dispersion compositions prepared in Examples 3-1 to 3-12 and Comparative Examples 3-1 and 3-2 were evaluated for redispersibility and storage stability by the following methods, and the results are shown in Table 5 below.

[0163] [Redispersibility evaluation method] The dispersion compositions prepared in Examples 3-1 to 3-12 and Comparative Examples 3-1 and 3-2 were stored at room temperature for 24 hours, and then 10 g of each dispersion composition was placed in a vial containing 15 mL of water and stirred for 1 hour using a magnetic bar to prepare a sample. The degree of dispersion of the dispersoids in the prepared sample was then observed with the naked eye. XX: The dispersion state of the dispersoid is the same as that immediately after the production of the dispersion composition. ○: The dispersion state of the dispersoid is such that small lumps are floating compared to the state immediately after the preparation of the dispersion composition. ×: The dispersed state of the dispersoid is such that large lumps are floating compared to the state immediately after the preparation of the dispersion composition. ××: Dispersoids are not dissolved in water

[0164] [Storage stability evaluation method] Samples were prepared in the same manner as described in the redispersibility evaluation method, and then each prepared sample was stored at room temperature for 1 hour, after which the degree of aggregation and precipitation of the dispersoids was visually observed. ○○: Dispersoids do not aggregate or precipitate ○: A small amount of dispersoids aggregates and precipitates ×: Most of the dispersoids aggregate and precipitate

[0165] [Table 5]

[0166] As shown in Table 5, in the case of Examples 3-1 to 3-12 of the present invention, they exist in a solid state at room temperature and have excellent storage stability, making them easy to store for long periods of time and also demonstrating excellent redispersibility. However, in Comparative Examples 3-1 and 3-2, in which the dispersion medium was in a liquid state at room temperature, the dispersoids became entangled and aggregated into small lumps. As a result, redispersibility decreased. Furthermore, aggregation and precipitation occurred during long-term storage at room temperature, confirming poor storage stability.

Claims

1. A solid dispersion comprising a dispersoid and a dispersion medium in which the dispersoid is dispersed, the dispersoid is an organic particle, an inorganic particle, or a mixture thereof, the dispersion medium is a non-aqueous dispersion medium in a solid state at room temperature, the non-aqueous dispersion medium is at least one selected from the group consisting of anhydrosugar alcohols, polyester polyols, and combinations thereof; A solid dispersion that is free of dispersants and surfactants.

2. 2. The solid dispersion according to claim 1, wherein the inorganic particles are selected from the group consisting of iron, aluminum, chromium, nickel, cobalt, zinc, tungsten, indium, tin, palladium, zirconium, titanium, copper, silver, gold, platinum, kaolin, clay, talc, mica, bentonite, dolomite, calcium silicate, magnesium silicate, asbestos, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, barium sulfate, aluminum sulfate, aluminum hydroxide, iron hydroxide, aluminum silicate, zirconium oxide, magnesium oxide, aluminum oxide, titanium oxide, iron oxide, zinc oxide, antimony trioxide, indium oxide, indium tin oxide, silicon carbide, silicon nitride, boron nitride, barium titanate, diatomaceous earth, carbon black, graphite, rock wool, glass wool, glass fiber, graphene, carbon fiber, carbon nanofiber, carbon nanotube, an alloy of two or more metals thereof, or a mixture of two or more metals thereof.

3. 2. The solid dispersion according to claim 1, wherein the organic particles are selected from the group consisting of an azo compound, a diazo compound, a condensed azo compound, a thioindigo compound, an indanthrone compound, a quinacridone compound, an anthraquinone compound, a benzimidazolone compound, a perylene compound, a phthalocyanine compound, an anthrapyridine compound, a dioxazine compound, a polyethylene resin, a polypropylene resin, a polyester resin, a nylon resin, a polyamide resin, an aramid resin, an acrylic resin, a vinylon resin, a urethane resin, a melamine resin, a polystyrene resin, polylactic acid, acetate fiber, cellulose, hemicellulose, lignin, chitin, chitosan, starch, polyacetal, polycarbonate, polyphenylene ether, polyether ether ketone, polyether ketone, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polysulfone, polyphenylene sulfide, polyimide, or a mixture thereof.

4. 2. The solid dispersion according to claim 1, wherein the dispersion medium is at least one selected from the group consisting of tetritan, pentitan, heptitan, sorbitan, mannitan, iditan, galactitan, isosorbide, isomannide, isoidide, butylene adipate diol, 1,6-hexane adipate diol, and combinations thereof.

5. 2. The solid dispersion according to claim 1, wherein the content of the dispersoid is 0.0001 to 95 parts by weight per 100 parts by weight of the dispersion medium.

6. The solid dispersion according to claim 1, which is a room temperature solid dispersion for chain extension.

7. A dispersion composition comprising the solid dispersion according to any one of claims 1 to 6.

8. mixing the dispersoid and the dispersion medium; and melting the dispersion medium in the mixture; A method for producing a solid dispersion comprising: the dispersoid is an organic particle, an inorganic particle, or a mixture thereof, the dispersion medium is a non-aqueous dispersion medium in a solid state at room temperature, the non-aqueous dispersion medium is at least one selected from the group consisting of anhydrosugar alcohols, polyester polyols, and combinations thereof; A method for producing a solid dispersion that does not contain a dispersant or a surfactant.

9. 9. The method for producing a solid dispersion according to claim 8, wherein the step of melting the dispersion medium in the mixture is carried out by removing water by applying a vacuum at a temperature equal to or higher than the melting point of the dispersion medium, thereby melting the mixture.

10. 10. A chain-extended polyurethane prepared by reacting a polyurethane prepolymer with the solid dispersion of claim 6.

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